Asymmetric
mandibular prognathism has varied causes; but often there is excess
growth of the lower jaw (condylar head) at one of the temporomandibular
joints (TMJ). When this happens, there is a primary effect on the
lower jaw and secondary effects on the upper jaw and chin. The
extent of deformity will be dependent on the timing of the unilateral
(one sided) condylar overgrowth in relation to any further (residual)
growth of the facial bones.

A combined orthodontic and surgical approach is required to improve
the occlusion (bite), facial symmetry and facial proportions.